the palosabre this contingency is simply and completely guarded against. Many flowers have contrivances for preventing useless insects from obtaining access to the nectaries. Amongst our English flowers there are scores of interesting examples, and I shall describe the fertilisation of one, the common foxglove, on account of the exceeding simplicity with which this object is effected, and to draw the attention of all lovers of nature to this branch of a subject on which the labours of Darwin and other naturalists have of late years thrown a flood of light. The pollen of the foxglove (Digitalis purpurea) is carried from one flower to another by the humble-bee, who, far more than the hive bee, that "improves each shining hour," deserves to be considered the type of steady, persevering industry. It improves not only the hours of sunshine, but those of cloud, and even rain; and, long before the honey-bee has ventured from its door, is at work bustling from flower to flower, its steady hum changing to an importunate squeak as it rifles the blossoms of their sweets. The racemes of purple bells held up by the foxglove are methodically visited by it, commencing at the bottom flower, and ascending step by step to the highest. The four stamens and the pistil of the foxglove are laid closely against the upper side of the flower. First a stamen on one side opens its anthers and exposes its pollen. The humble-bee, as it bustles in and out, brushes this off. Then another stamen exposes its pollen on the other side, then another and another; but not till all the pollen has been brushed off does the cleft end of the pistil open, and expose its viscid stigma. The humble-bee brushes off the pollen onto its hairy coat from the upper flowers of one raceme and carries it direct to the lowest flowers of another, where the viscid stigmas are open and ready to receive it. If the humble-bee went first to the upper flowers of the spike and proceeded downwards, the whole economy of this plant to procure cross fertilisation would be upset.* (* Darwin mentions having seen humble-bees visiting the flowering spikes of the Spiranthes autumnalis (ladies' tresses), and notices that they always commenced with the bottom flowers, and crawling spirally up, sucked one flower after the other, and shows how this proceeding ensures the cross fertilisation of different plants.--"Fertilisation of Orchids" page 127.) The open flower of the foxglove hangs downwards. The lower part, or dilated opening of the tube, is turned outwards, and has scattered stiff hairs distributed over its inner surface; above these the inside of the flower hangs almost perpendicularly, and is smooth and pearly. The large humble-bee bustles in with the greatest ease, and uses these hairs as footholds whilst he is sucking the honey; but the smaller honey-bees are impeded by them, and when, having at last struggled through them, they reach the pearly, slippery precipice above, they are completely baffled.